1. Field of the Invention
The present invention relates to a magnetic head for magnetically recording and/or reproducing data from magnetic disk media, such as a magnetic disk cartridge.
2. Description of the Related Art
Conventional magnetic disk cartridges are provided comprising: a flexible magnetic disk medium formed by a discoid substrate formed of a flexible polyester sheet or the like having magnetic layers formed on both sides thereof; and a case having a window for insertion of a magnetic head. The magnetic disk media is rotatably housed within the case. This type of magnetic disk cartridge is mainly used as recording media for computers, due to its advantages regarding ease of use and low cost.
A drive apparatus for driving a magnetic disk cartridge of the aforementioned construction generally comprises: a rotating drive means for rotating the magnetic disk medium; a magnetic head for performing recording and/or reproduction of signals from the magnetic disk medium; and a magnetic head arm on which the magnetic head is mounted, for moving the magnetic head in the radial direction of the magnetic disk medium. With regard to a drive apparatus of this structure, data is recorded onto and reproduced from concentric tracks of the magnetic disk medium by the relative movement between the magnetic head and the magnetic disk medium in the circumferential direction thereof, as well as movement of the magnetic head in the radial direction of the magnetic disk medium by the movement of the magnetic head arm.
Note that the aforementioned magnetic head basically comprises: a head slider that approaches or contacts the magnetic disk medium; rails or pads formed on the head slider; and head elements provided on the rails or pads.
Regarding the conventional magnetic head of the basic structure described above, a single or a plurality of rails or pads are formed on the head slider. A head element is formed on one of the rails or the pads. Note that there are provided magnetic heads having a head element formed on each of a pair of rails or pads. However, even magnetic heads of this construction, only one head element on one of the rails or pads is actually utilized for magnetic recording and/or reproduction. That is, these magnetic heads are constructed in this manner due to magnetic heads for facing both sides of a magnetic disk medium being produced in a common step.
Recently, there is a widespread demand for miniaturization of magnetic disk cartridges, so that they can be used as low cost removable media for portable equipment. A problem of reduced data transfer rate arises along with a decrease in the diameter of magnetic disk media. If the data transfer rate becomes slow, recording/reproduction of data in real time becomes impossible in a video camera that processes motion pictures, for example.
In addition, in the case that the diameter of magnetic disk media is decreased, the recording density is increased, in order not to decrease recording capacity thereof. That is, it is often the case that the tracks are made narrower. However, if the tracks are made narrower, tracking control, by which the magnetic head follows the tracks, becomes difficult. That is, as the tracks become narrower, servo signals which are used for tracking control become more likely to be influenced by signal dropouts and the like, thereby causing failures in the tracking control.